The Compatriot Win Effect and Behavioural Biases in Lottery Markets
利用西班牙国家彩票圣诞抽奖中头奖在各省的准随机分配，研究发现中奖省份后续彩票销量显著增加，该效应通过媒体关注度提升彩票需求。
ABSTRACT This paper presents evidence to support the compatriot win effect as a behavioural bias in lottery demand. We exploit the quasi‐random assignment of the jackpot prize across provinces in the Christmas draw of the Spanish National Lottery to examine whether lottery sales increase in jackpot‐winning provinces in subsequent draws. Using difference‐in‐differences with staggered treatment timing, we present robust evidence that lottery sales in provinces where the jackpot is awarded experience a significant boost in subsequent draws. The compatriot win effect appears to operate through increased media coverage in winning regions, which boosts lottery demand by enhancing the salience of the draw.